A throttle body is instrumental in internal combustion engines by functioning to regulate the flow of air into the engine thereby regulating engine power. The throttle body is typically located downstream from an air cleaner or air filter and upstream of an air intake manifold and includes a throttle plate (e.g., one or more butterfly valves) which is movable between a closed position, one or more partially open positions, and a fully open position to regulate the flow of air into the air intake manifold of the engine.
In modern fuel-injected engines, throttle bodies are electronically controlled by the engine's control unit. A sensor or an airflow detector coupled with the throttle body sends throttle plate position information and/or airflow information to the engine control unit, and a sensor coupled with the vehicle's accelerator pedal receives driver input and/or detects the position of the accelerator pedal and sends information to the engine control unit. The engine control unit, in turn, controls an actuating mechanism coupled with the throttle plate and/or with the throttle body which moves the throttle plate between the closed position, the one or more partially open positions, and the fully open position to increase or decrease engine speed or power output and/or to maintain a minimum idling speed of the engine.
Some engines, such as V-shaped engines, include air intake manifolds with two separate portions and two separate intake ports which supply air to two groups of cylinders on both sides of the V-shape. For engines having two air intake manifold portions and/or intake ports a dual-port throttle body is generally used to supply airflow to both portions of the air intake manifold via the two intake ports. Throttle bodies with two output ports are commonly known as twin throttle bodies or dual-port throttle bodies and typically include a large intake opening upstream of the throttle plate and two output ports downstream of the throttle plate. Dual-port throttle body throttle plates are generally configured to include two butterfly valves actuated by a common shaft with each butterfly valve controlling airflow through one of the two output ports of the dual-port throttle body.
Dual-port throttle bodies have a wall structure or bridge separating the two ports. Consequently, air entering the throttle body encounters the wall structure. Depending of the configuration of the wall structure, the flow of air through the throttle body and into the intake manifold can be impeded in a way that detrimentally affects the performance of the engine. Current throttle bodies have various wall structure designs which impede the flow of air through the throttle body. For example, some throttle bodies have wall structures with large exposed surfaces positioned at blunt angles relative to the direction of the airflow through the throttle body and have abrupt contour changes which create high-pressure and low-pressure areas in the throttle body. Other wall structures impede airflow through the throttle body by increasing friction and by directing airflow through an oblique flow path relative to the output ports. Finally, some wall structures result in increased noise during engine operation and in decreased and/or sub-optimal volumes of air flowing into the engine, thereby reducing engine power and efficiency and decreasing gas mileage.